/* 优化后的公共样式 */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    height: 100%;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    
    /* 使用CSS渐变背景替代图片背景 */
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    
    /* 添加微妙的纹理效果 */
    background-color: #f0f2f5;
}

.nav {
    height: 60px;
    background: linear-gradient(135deg, #2c3e50, #1a2a3a);
    color: white;
    line-height: 60px;
    padding-left: 30px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
    font-size: 22px;
    font-weight: 600;
}

.container {
    width: 100%;
    height: calc(100% - 60px);
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 通用按钮样式 */
.btn {
    border: none;
    outline: none;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

.btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* 通用输入框样式 */
.input-field {
    width: 100%;
    height: 45px;
    padding: 0 15px;
    font-size: 16px;
    border: 2px solid #ddd;
    border-radius: 8px;
    transition: border-color 0.3s ease;
}

.input-field:focus {
    border-color: #4a90e2;
    outline: none;
    box-shadow: 0 0 0 2px rgba(74, 144, 226, 0.2);
}